DESCRIPTION: (Applicant's Abstract) Few data exist in the U.S. to document the prevalence of ocular disorders among preschool age children. There is even less information on the age and race-specific incidence of pediatric ocular disorders such as amblyopia, strabismus and anisometropia. We propose to address this lack of basic information by conducting a combined population-based prevalence and incidence survey in the multiethnic communities of northeast Baltimore. Over 39,000 households in 26 census tracts will be screened for children 6 months through 4 years of age in order to identify 6,300 eligible children. Assuming an 80% response rate, this will yield 5,000 subjects for study. All subjects will receive an enrollment interview, and detailed ophthalmologic screening examinations at baseline, and again at 12 and 24 months post baseline. The exam will include measures of refraction, visual acuity, ocular motility and alignment, and binocularity. All subjects abnormal on screening will receive a comprehensive ophthalmological examination by a pediatric ophthalmologist. The analysis will focus on estimation of age-race specific prevalence and incidence rates together with an assessment of risk factors for these ocular disorders.